Delney + Hare Apparent deck now invalid in Brawl?

Updated my game today and got the attack with 45 creatures quest so I thought it would be the perfect time to whip out Delney + Hare Apparent to attach with a lot of creatures. But now Arena is saying it's an invalid deck? There's 60 Hare Apparents and the client is notifying me that 59 cards are invalid, so it's like it's not picking up on the fact that you can have multiple copies. Did I miss an announcement restricting this card in Brawl?

https://preview.redd.it/cf5c3oakjobf1.jpg?width=403&format=pjpg&auto=webp&s=3868ea929c8f1eb1663d5cc3a92f6d567b499c35